CBSE 2025 · Region 5 · Set 3 · Q17 · 2 marks
Find the effective resistance of the network of resistors between points A and F as shown in the figure.
Marking-scheme solution
$\displaystyle R_{B C D}=2+4=6 \Omega$
$\displaystyle R_{B D}=\frac{3 \times 6}{6+3}=2 \Omega$
$\displaystyle R_{B D E}=2+8=10 \Omega$
$\displaystyle R_{B E}=\frac{40 \times 10}{40+10}=8 \Omega$
$\displaystyle R_{A F}=7+8+5=20 \Omega$
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